Smoking cigarettes has the same effect as cutting the life span by close to five years, according to a mortality risk chart released Tuesday in the US Journal of the National Cancer Institute.
"The effect of smoking on the chance of dying is similar to the effect of adding five to 10 years of age," the study said.
"For both men and women, smoking increases the risk of death by nearly the same magnitude as adding five years to a person's age."
The figures were derived by compiling death and health risk statistics from various agencies such as the American Cancer Society and National Center for Health Statistics, and were arranged into 10-year risk charts.
"For example, a 55-year-old man who smokes has about the same 10-year risk of death from all causes as a 65-year-old man who never smoked," it said.
Among women who never smoked, the 10-year risk rates of dying from breast cancer and heart disease were similar until age 60, after which heart disease was the biggest killer.
"For women who currently smoke, the chance of dying from heart disease or lung cancer exceeds the chance of dying from breast cancer from age 40 on."
The study, which aimed to help doctors convey the risks of smoking, was led by Lisa Schwartz of the Department of Veterans Affairs Medical Center in Vermont.
"We hope that the availability of these simple charts will facilitate physician-patient discussion about disease risk and help people understand where to focus risk reduction efforts," the authors wrote.